Capital Stock (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Class of Warrant or Right [Line Items]
Common stock authorized (in shares)	150,000,000
Preferred stock authorized (in shares)	4,000,000
Common stock, par value (usd per share)	$ 1.25	$ 1.25
Preferred stock authorized, par value (in dollars per share)	$ 1.25
Preferred stock, shares issued (in shares)	0
Shares Authorized to Be Purchased [Roll Forward]
Shares Purchased	0
Treasury Stock
Shares Authorized to Be Purchased [Roll Forward]
Shares Purchased	1,321,072	0	0